HTML code formatter

The HTML code formatter online standardizes markup to improve readability and collaboration. It accepts HTML input and applies deterministic rules for indentation, attribute layout, and whitespace. The tool preserves doctype and comments, leaves script and style blocks untouched, and can wrap long attribute lists for better diffs. It runs in the browser, avoiding server round-trips and enabling instant feedback for developers and learners. Output is stable, reproducible, and suitable for code reviews, educational exercises, and team handoffs. By concept, it builds a DOM-like representation of the input and serializes back into well-formed HTML using stable indentation (2 spaces by default) and predictable attribute formatting. Optional options allow adjusting indent size, enabling attribute wrapping, or preserving preformatted content. The formatter is designed to be idempotent: formatting already formatted HTML yields the same result. It handles common edge cases such as stray whitespace, mixed indentation, and minor tag variations. Audience and value: developers, educators, and teams benefit from cleaner diffs, faster reviews, and consistent markup across projects. Unique differentiators include client-side operation for privacy, diff-friendly output, and configurable formatting rules that align with team conventions. Use cases include preparing HTML for pull requests, teaching markup best practices, and standardizing templates across multiple pages.